Air-permeable waterproof composite fabric and preparation method thereof

Abstract

The application provides a breathable waterproof composite fabric and a preparation method thereof, and belongs to the technical field of textiles. The fabric comprises the following preparation steps: mixing PTFE emulsion, polyethylene oxide, anhydrous ethanol, PNIPAM@PSF core-shell capsules and deionized water, defoaming, spinning and sintering to obtain a nanofiber membrane; placing alkalized PET fiber cloth into an HFBA / HEA impregnating solution, heating, dehydrating and baking to obtain an outer base cloth; mixing polyurethane resin, DMF, propylene glycol methyl ether, a defoaming agent and deionized water to obtain a PU coating liquid; stacking the outer base cloth and the nanofiber membrane, and hot-pressing to obtain a PET / PTFE composite material; coating the PU coating liquid to one side of the nanofiber membrane of the PET / PTFE composite material, heating to obtain an inner layer membrane, and cooling and standing to obtain the breathable waterproof composite fabric. The fabric prepared by the application has good mechanical strength, air permeability and waterproof performance.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to a breathable and waterproof composite fabric and its preparation method. Background Technology

[0002] Waterproof and breathable fabrics are commonly used in outdoor sportswear, special protective equipment, and civilian functional textiles. Their core performance lies in simultaneously possessing good hydrostatic pressure resistance, windproofness, and thermal comfort. Existing waterproof and breathable materials mainly include polyurethane coatings, polytetrafluoroethylene (PTFE) microporous membranes, and nanofiber membrane composites. Among these, nanofiber membranes have attracted much attention due to their high chemical stability, uniform pore structure, and excellent breathability. However, nanofiber membranes themselves lack sufficient mechanical support and are prone to pore deformation under external forces, thus affecting their waterproof performance. Furthermore, while the nanoscale pore structure achieves high breathability, it often leads to a decrease in hydrostatic pressure resistance, making it difficult to simultaneously achieve both waterproof and breathable performance.

[0003] Nanofiber membranes need to be laminated with base fabric materials to form practically applicable fabric structures. However, the interfacial compatibility between conventional PET fiber base fabrics and nanofiber membranes is poor, making them prone to delamination during hot pressing or use. Although existing technologies have attempted to improve their bonding strength through surface roughening, introducing adhesives, or using fluorinated finishing agents, the chemical bonding ability of the composite interface is limited, making it difficult to simultaneously guarantee washability, water pressure resistance, and long-term stability. Furthermore, traditional fabrics lack breathability in humid and hot environments. When the body sweats or the ambient humidity increases, the migration rate of gaseous water within the fabric is limited, leading to stuffiness and discomfort when worn.

[0004] Patent application CN113276520A discloses a PTFE composite fabric. The composite fabric includes an outer layer, a composite layer, and an inner layer. The outer layer is bonded to the outer surface of the composite layer, and the inner layer is bonded to the inner surface of the composite layer. The outer layer comprises the following materials: 10% high-grade FDY filament, 20% combed pure cotton yarn, 20% flame-retardant polyester fiber, 6% flame-retardant acrylic fiber, 14% bamboo fiber, 15% cotton fiber, 12% nylon fiber, and 13% spandex fiber. The composite layer comprises the following materials: 30% PTFE membrane, 30% cotton fiber, 20% nylon fiber, and 20% spandex fiber. The inner layer comprises the following materials: 10% high-grade FDY filament, 20% combed pure cotton yarn, 35% flame-retardant polyester fiber, 15% flame-retardant acrylic fiber, 8% nylon fiber, and 12% spandex fiber. Although the PTFE composite fabric in this solution has a certain degree of waterproof performance, the microporous structure of the PTFE membrane also restricts the migration of gaseous water, making it difficult to effectively improve breathability.

[0005] In summary, there is a need to provide a breathable and waterproof composite fabric and its preparation method to solve the problems existing in the prior art. Summary of the Invention

[0006] In view of this, the present invention provides a breathable and waterproof composite fabric and its preparation method, which enables the fabric to have good breathability, waterproof performance and mechanical strength.

[0007] To achieve the above objectives, a method for preparing a breathable and waterproof composite fabric is provided, wherein the fabric comprises at least an outer base fabric, a nanofiber membrane, and an inner membrane stacked sequentially, and includes the following preparation steps:

[0008] S1. PTFE emulsion, polyethylene oxide, anhydrous ethanol, PNIPAM@PSF core-shell capsules and deionized water are mixed and stirred, degassed under negative pressure, electrospun and sintered to obtain nanofiber membranes.

[0009] S2. The alkalized PET fiber cloth is placed in HFBA / HEA impregnation solution, heated, dehydrated and dried, and baked to obtain the outer base cloth;

[0010] S3. Mix and stir polyurethane resin, DMF, propylene glycol methyl ether, defoamer and deionized water to prepare PU coating liquid;

[0011] S4. After laminating the outer base fabric and the nanofiber membrane, hot-press the mixture, coat the nanofiber membrane with PU coating liquid, heat it to form an inner membrane on the nanofiber membrane, cool and let it stand to obtain a breathable and waterproof composite fabric.

[0012] The PNIPAM@PSF core-shell capsules are prepared by mixing and stirring N-isopropylacrylamide, N,N'-methylenebisacrylamide, ammonium persulfate and deionized water, heating and reacting, cooling, adding bisphenol A polysulfone, dichloromethane and tetrahydrofuran, stirring to form an emulsion, adding dropwise to a polyvinyl alcohol solution, heating, centrifuging and washing.

[0013] To address the challenge of simultaneously achieving good breathability, waterproofing, and mechanical strength in breathable and waterproof composite fabrics, this invention improves both the nanofiber membrane and the outer base fabric. The nanofiber membrane incorporates a PNIPAM@PSF core-shell capsule with PNIPAM (N-isopropylacrylamide) as the core and PSF (bisphenol A polysulfone) as the shell, enhancing both the waterproofing and breathability of the composite fabric. The outer base fabric, treated with HFBA / HEA impregnation solution, forms a copolymer membrane with fluorinated segments on the PET fiber surface, enhancing its fluorine-fluorine compatibility and mechanical interlocking with the nanofiber membrane. The outer base fabric, nanofiber membrane, and inner membrane are then sequentially composited, thereby improving the overall breathability, waterproofing, and mechanical strength of the breathable and waterproof composite fabric.

[0014] This invention achieves a synergistic improvement in the breathability and waterproof performance of nanofiber membranes by introducing PNIPAM@PSF core-shell capsules. When ambient humidity increases, the PNIPAM core actively adsorbs surrounding gaseous water. Its hydrophilic segments interact with gaseous water molecules, transforming from a contracted state to an expanded state, forming a water-rich transport region within the membrane. This region contains numerous hydrophilic groups that can interact with gaseous water, resulting in higher solubility and lower diffusion resistance of gaseous water within the PNIPAM@PSF core-shell capsules, thereby enhancing the migration efficiency of gaseous water in the nanofiber membrane. Compared to traditional methods where gaseous water diffuses solely through breathable pores, the water-rich transport zone effectively constructs multiple gaseous water transport nodes within the nanofiber membrane. This shortens the diffusion path of gaseous water within the membrane and reduces diffusion tortuosity, thereby improving the membrane's breathability. In humid and hot environments, the PNIPAM core continuously adsorbs gaseous water and remains in an expanded state, forming a stable breathable path, which enhances the breathability of the nanofiber membrane and thus strengthens the overall breathability of the fabric.

[0015] Furthermore, the PSF shell enhances the nanofiber membrane's ability to block liquid water. The hydrophobicity of the PSF shell strengthens the water-repellent properties of the nanofiber membrane's pores, making it difficult for liquid water to wet and expand within the pores. Simultaneously, the PNIPAM@PSF core-shell capsules more easily fill larger local pores within the nanofiber membrane's network structure. Their occupancy effectively reduces the membrane's maximum effective pore size, decreasing weak paths through which liquid water can penetrate, thereby improving hydrostatic pressure resistance. The high rigidity of the PSF shell also serves as a local support point, enhancing the pore structure's resistance to deformation under external water pressure, ensuring pore stability under high pressure conditions, and thus improving waterproofing performance.

[0016] This invention involves immersing PET fiber fabric in an HFBA / HEA impregnation solution, utilizing the hexafluorobutyl acrylate (HFBA) and 2-hydroxyethyl acrylate (HEA) contained in the impregnation solution for copolymerization, and then curing in situ during the baking stage to form a copolymer film, thus obtaining an outer base fabric with a fluorinated copolymer film. This copolymer film is rich in -CF2- / -CF3 groups, exhibiting good fluorine-fluorine compatibility with the fluorocarbon segments on the surface of the nanofiber membrane. Simultaneously, the acrylate backbone in the copolymer film enhances the interfacial adhesion with the PET fibers, forming a stable interfacial transition structure between the outer base fabric and the nanofiber membrane, thereby improving the adhesion strength between them. During subsequent hot pressing, the copolymer film further penetrates into the local pores of the nanofiber membrane, creating a mechanical interlocking effect with the nanofiber membrane network, further improving the structural stability between the nanofiber membrane and the outer base fabric, preventing delamination, enhancing the hydrostatic pressure resistance of the breathable and waterproof composite fabric, and improving the fabric's waterproof performance.

[0017] Optionally, in step S2, before dehydration and drying, the alkalized PET fiber cloth also undergoes heating swelling and cooling recrystallization treatment.

[0018] Optionally, in step S2, N,N-dimethylformamide and ethylene glycol are mixed and heated to 80-90°C. Alkaliized PET fiber cloth is added and soaked for 5-10 minutes to swell. The swollen alkaliized PET fiber cloth is placed in HFBA / HEA impregnation solution, heated to 70-80°C and kept at a constant temperature for 2-3 hours, cooled to 5-10°C and cooled for 20-30 minutes, dehydrated by rollers to a moisture content of 15%-25%, dried at 100-110°C for 1-3 minutes, and baked at 150-170°C for 40-80 seconds to obtain the outer base fabric.

[0019] This invention employs a heating-swelling and cooling-recrystallization roughening process. Amorphous regions on PET fiber fabric swell in a mixed solvent of N,N-dimethylformamide / ethylene glycol at 80-90°C. Subsequently, after heating and copolymerizing in an HFBA / HEA impregnation solution, the film is cooled to 5-10°C, promoting recrystallization of the PET fiber fabric surface. This increases the surface roughness, thereby improving the specific surface area of ​​the PET fiber fabric and constructing dense micro-scale pores on the fiber surface. This provides more anchoring sites for the subsequent copolymer film deposited on the PET fiber fabric surface, making it easier for the copolymer to penetrate into the micropores and solidify. Simultaneously, the crystalline protrusions formed by swelling and recrystallization enhance the structural stability between the PET fiber fabric and the nanofiber membrane during subsequent hot pressing, improving the hydrostatic pressure resistance of the breathable and waterproof composite fabric and further enhancing its waterproof capability.

[0020] Optionally, in step S1, PTFE emulsion, polyethylene oxide, anhydrous ethanol, PNIPAM@PSF core-shell capsules and deionized water are mixed and stirred at 300~400 rpm for 1.5~2.5 h, and degassed for 10~20 min under a negative pressure of -0.09~-0.07 MPa to obtain an electrospinning solution, which is then fed into an electrospinning machine for electrospinning. The solution is heated to 340~345℃ at a rate of 2~4℃ / min and sintered for 8~12 min, and then cooled to obtain a nanofiber membrane.

[0021] In this invention, negative pressure degassing improves the uniformity and stability of the electrospinning solution, allowing the PNIPAM@PSF core-shell capsules to be fully dispersed in the electrospinning solution and reducing the generation of bubble defects, thereby improving the stability of the jet flow during electrospinning.

[0022] Optionally, in the preparation process of the PNIPAM@PSF core-shell capsules, N-isopropylacrylamide, N,N'-methylenebisacrylamide, ammonium persulfate and deionized water are mixed and stirred, heated to 65~75℃ and kept at a constant temperature for 2~4h, cooled to room temperature, bisphenol A type polysulfone, dichloromethane and tetrahydrofuran are added, and stirred at 8000~12000rpm for 1~3min to form an emulsion. The emulsion is added dropwise to a 1~2wt% polyvinyl alcohol solution, stirred at 3000~5000rpm for 5~10min, heated to 30~40℃ and stirred for 4~5h, centrifuged and washed, and dried at 40~50℃ for 1~2h to obtain the product.

[0023] In this invention, PNIPAM@PSF core-shell capsules with a PNIPAM core and a PSF shell are constructed through the above-described polymerization and emulsification curing. The hygroscopicity of the PNIPAM core improves the migration efficiency of gaseous water in the nanofiber membrane; the hydrophobicity of the PSF shell enhances the water-repellent ability of the nanofiber membrane, while the PSF shell prevents structural damage caused by external environmental influences during subsequent processing.

[0024] Optionally, in step S3, polyurethane resin, DMF, propylene glycol methyl ether, RH-9510 defoamer and deionized water are mixed and stirred at 300~500 rpm for 1~2 hours, and then filtered through a 0.45μm filter to obtain PU coating liquid.

[0025] Optionally, in step S4, after the outer base fabric and the nanofiber membrane are laminated, they are hot-pressed at a temperature of 130~150℃ and a pressure of 0.25~0.35MPa at a speed of 3~5m / min, cooled to 30~50℃, and the PU coating liquid is uniformly coated onto the nanofiber membrane. The membrane is then heated to 100~130℃ and kept at a constant temperature for 3~6 minutes to form an inner membrane on the nanofiber membrane. After cooling to room temperature, the membrane is allowed to stand and age for 20~30 hours to obtain a breathable and waterproof composite fabric.

[0026] In this invention, by hot-pressing the outer base fabric and the nanofiber membrane together, the outer base fabric and the nanofiber membrane can be fully bonded and stably mechanically interlocked, so that the two layers of materials form a continuous, uniform and firm interface structure.

[0027] Optionally, the alkalized PET fiber cloth is prepared by mixing PET fiber cloth and sodium hydroxide solution, maintaining the temperature at 95~98℃ for 20~30 minutes, and then filtering and washing.

[0028] In this invention, by alkalizing the PET fiber fabric, sodium hydroxide can hydrolyze the ester bonds in the PET molecular chain, causing moderate etching and roughening of the fiber surface and forming more hydrophilic groups such as carboxyl and hydroxyl groups. This not only improves the wettability and permeability of the subsequent impregnation solution, but also enhances the interfacial bonding ability between the PET fiber and the subsequent copolymer film through the alkalization process.

[0029] A breathable and waterproof composite fabric, wherein the nanofiber membrane comprises the following raw materials in parts by weight: 90-120 parts of 60wt% PTFE emulsion, 15-25 parts of polyethylene oxide, 220-255 parts of anhydrous ethanol, 15-18 parts of PNIPAM@PSF core-shell capsules, and 80-100 parts of deionized water; the outer base fabric comprises the following raw materials in parts by weight: 120-130 parts of alkalized PET fiber cloth, 40-60 parts of N,N-dimethylformamide, 40-60 parts of ethylene glycol, and 1100-1600 parts of HFBA / HEA impregnation solution; the inner membrane is made of PU coating liquid, wherein the PU coating liquid comprises the following raw materials in parts by weight: 30-35 parts of 35wt% polyurethane resin, 50-60 parts of DMF, 4-6 parts of propylene glycol methyl ether, 0.1-0.3 parts of RH-9510 defoamer, and 8-10 parts of deionized water.

[0030] Optionally, the PNIPAM@PSF core-shell capsule comprises the following raw materials in parts by weight: 5-8 parts of N-isopropylacrylamide, 0.2-0.5 parts of N,N'-methylenebisacrylamide, 0.1-0.3 parts of ammonium persulfate, 80-100 parts of deionized water, 10-15 parts of bisphenol A polysulfone, 60-75 parts of dichloromethane, and 10-20 parts of tetrahydrofuran; the alkalized PET fiber cloth comprises the following raw materials in parts by weight: 120-130 parts of PET fiber cloth and 850-1000 parts of 3wt% sodium hydroxide solution.

[0031] The above-described technical solution of the present invention has at least the following beneficial effects:

[0032] This invention achieves a synergistic improvement in the breathability and waterproofness of nanofiber membranes through PNIPAM@PSF core-shell capsules. The PSF shell provides excellent hydrophobicity and mechanical support, which can adjust the effective pore size of the nanofiber membrane and enhance its structural stability; the PNIPAM core, as a humidity-responsive unit, undergoes hygroscopic expansion in humid and hot environments, providing an additional transport path for gaseous water.

[0033] The PNIPAM core actively adsorbs surrounding gaseous water, increasing its solubility and reducing diffusion resistance within the PNIPAM@PSF core-shell capsule, thereby enhancing its migration rate. The PSF shell also improves the nanofiber membrane's barrier effect against liquid water; its hydrophobicity enhances the water-repellent capacity of the pores, preventing liquid water wetting and expansion. The occupancy effect of the PNIPAM@PSF core-shell capsule reduces the pore size of the nanofiber membrane, decreasing the liquid water permeation path and thus improving hydrostatic pressure resistance, further enhancing overall waterproof performance.

[0034] The PET fiber fabric treated with HFBA / HEA forms a copolymer film rich in -CF2- / -CF3 groups on its surface. This film has good fluorine-fluorine compatibility with the fluorocarbon segments on the surface of the nanofiber film. At the same time, the acrylate backbone in the copolymer film enhances its interfacial adhesion with PET fibers, improves the structural strength between the outer base fabric and the nanofiber film, reduces the risk of interlayer delamination, and enhances the waterproof capability of the fabric. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the breathable and waterproof composite fabric in an embodiment of the present invention.

[0036] In the picture:

[0037] 1. Outer base fabric; 2. Nanofiber membrane; 3. Inner membrane. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are some embodiments of the present invention, and all other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0039] Example 1

[0040] Five parts of N-isopropylacrylamide (PNIPAM), 0.2 parts of N,N'-methylenebisacrylamide, 0.1 parts of ammonium persulfate, and 80 parts of deionized water were mixed and stirred until homogeneous. The mixture was heated to 65°C and kept at that temperature for 2 hours. After cooling to room temperature, 10 parts of bisphenol A polysulfone (PSF), 60 parts of dichloromethane, and 10 parts of tetrahydrofuran were added. The mixture was stirred at 8000 rpm for 1 minute to form an emulsion. The emulsion was then added dropwise to 200 parts of a 1 wt% polyvinyl alcohol solution and stirred at 3000 rpm for 5 minutes. The mixture was heated to 30°C and stirred continuously for 4 hours. After centrifugation and washing, the mixture was dried at 40°C for 1 hour to obtain PNIPAM@PSF core-shell capsules.

[0041] 90 parts of 60wt% PTFE emulsion, 15 parts of polyethylene oxide, 220 parts of anhydrous ethanol, 15 parts of PNIPAM@PSF core-shell capsules, and 80 parts of deionized water were mixed and stirred at 300 rpm for 1.5 h. The mixture was then degassed under a negative pressure of -0.09 MPa for 10 min to obtain an electrospinning solution. This solution was fed into an electrospinning machine with the electrospinning voltage set to 30 kV, the collection distance to 15 cm, and the liquid supply rate to 0.6 mL / h. The electrospinning solution was deposited onto a collecting roller and placed in a sintering furnace. The furnace was heated to 340 °C at a rate of 2 °C / min and sintered for 8 min. After cooling to room temperature, a nanofiber membrane was obtained.

[0042] 120 parts of PET fiber cloth and 850 parts of 3wt% sodium hydroxide solution were treated at 95℃ for 20 min, filtered and washed to obtain alkalized PET fiber cloth. 40 parts of N,N-dimethylformamide and 40 parts of ethylene glycol were mixed, heated to 80℃, and the alkalized PET fiber cloth was added and soaked for 5 min for swelling treatment. 250 parts of hexafluorobutyl acrylate (HFBA), 30 parts of 2-hydroxyethyl acrylate (HEA), 700 parts of anhydrous ethanol, 50 parts of ethyl acetate and 100 parts of deionized water were mixed to prepare HFBA / HEA impregnation solution. The swollen alkalized PET fiber cloth was placed in 1100 parts of HFBA / HEA impregnation solution, heated to 70℃ for 2 h, cooled to 5℃ for 20 min, dehydrated by rollers to a moisture content of 15%, dried at 100℃ for 1 min, and baked at 150℃ for 40 s to obtain the outer base fabric.

[0043] 30 parts of 35wt% polyurethane resin, 50 parts of DMF, 4 parts of propylene glycol methyl ether, 0.1 parts of RH-9510 defoamer and 8 parts of deionized water were mixed and stirred at 300 rpm for 1 hour. The mixture was then filtered through a 0.45 μm filter to obtain the PU coating liquid.

[0044] After the outer base fabric and nanofiber membrane are laminated, they are fed into a hot press laminating machine and hot-pressed at a temperature of 130℃ and a pressure of 0.25MPa at a speed of 3m / min. After cooling to 30℃, a PET / PTFE composite material is obtained. A PU coating liquid is uniformly coated onto one side of the nanofiber membrane of the PET / PTFE composite material and heated to 100℃ and kept at that temperature for 3 minutes to obtain the inner membrane. After cooling to room temperature, the membrane is allowed to stand and age for 20 hours to obtain a breathable and waterproof composite fabric composed of an outer base fabric 1, a nanofiber membrane 2, and an inner membrane 3.

[0045] Example 2

[0046] Eight parts of N-isopropylacrylamide (PNIPAM), 0.25 parts of N,N'-methylenebisacrylamide, 0.2 parts of ammonium persulfate, and 90 parts of deionized water were mixed and stirred until homogeneous. The mixture was heated to 70°C and kept at that temperature for 3 hours. After cooling to room temperature, 12 parts of bisphenol A polysulfone (PSF), 70 parts of dichloromethane, and 15 parts of tetrahydrofuran were added. The mixture was stirred at 10,000 rpm for 2 minutes to form an emulsion. The emulsion was then added dropwise to 250 parts of a 1.5 wt% polyvinyl alcohol solution and stirred at 4,000 rpm for 7 minutes. The mixture was heated to 35°C and stirred continuously for 4.5 hours. After centrifugation and washing, the mixture was dried at 45°C for 1.5 hours to obtain PNIPAM@PSF core-shell capsules.

[0047] 110 parts of 60wt% PTFE emulsion, 20 parts of polyethylene oxide, 240 parts of anhydrous ethanol, 17 parts of PNIPAM@PSF core-shell capsules, and 90 parts of deionized water were mixed and stirred at 350 rpm for 2 h. The mixture was then degassed for 15 min under a negative pressure of -0.08 MPa to obtain an electrospinning solution. The solution was fed into an electrospinning machine with the electrospinning voltage set to 35 kV, the collection distance to 17 cm, and the liquid supply rate to 0.85 mL / h. The electrospinning solution was deposited onto a collecting roller and placed in a sintering furnace. The temperature was increased to 342 °C at a rate of 3 °C / min and sintered for 10 min. After cooling to room temperature, a nanofiber membrane was obtained.

[0048] 125 parts of PET fiber cloth and 950 parts of 3wt% sodium hydroxide solution were treated at 96℃ for 25 min, filtered and washed to obtain alkalized PET fiber cloth. 50 parts of N,N-dimethylformamide and 50 parts of ethylene glycol were mixed, heated to 85℃, and the alkalized PET fiber cloth was added and soaked for 8 min for swelling treatment. 300 parts of hexafluorobutyl acrylate (HFBA), 4 parts of 2-hydroxyethyl acrylate (HEA), 800 parts of anhydrous ethanol, 75 parts of ethyl acetate and 150 parts of deionized water were mixed to prepare HFBA / HEA impregnation solution. The swollen alkalized PET fiber cloth was placed in 1300 parts of HFBA / HEA impregnation solution, heated to 75℃ for 2.5 h, cooled to 8℃ for 25 min, dehydrated by rollers to a moisture content of 20%, dried at 105℃ for 2 min, and baked at 160℃ for 60 s to obtain the outer base fabric.

[0049] 32 parts (35 wt%) of polyurethane resin, 55 parts of DMF, 5 parts of propylene glycol methyl ether, 0.2 parts of RH-9510 defoamer, and 9 parts of deionized water were mixed and stirred at 40 rpm for 1.5 h. The mixture was then filtered through a 0.45 μm filter to obtain the PU coating liquid.

[0050] After the outer base fabric and nanofiber membrane are laminated, they are fed into a hot press laminating machine. At a temperature of 140℃ and a pressure of 0.3MPa, they are hot-pressed at a speed of 4m / min. After cooling to 50℃, a PET / PTFE composite material is obtained. A PU coating liquid is uniformly coated onto one side of the nanofiber membrane of the PET / PTFE composite material and heated to 120℃ for 5 minutes to obtain the inner membrane. After cooling to room temperature, it is allowed to stand for aging for 25 hours to obtain a breathable and waterproof composite fabric composed of outer base fabric 1, nanofiber membrane 2 and inner membrane 3.

[0051] Example 3

[0052] Eight parts of N-isopropylacrylamide (PNIPAM), 0.5 parts of N,N'-methylenebisacrylamide, 0.3 parts of ammonium persulfate, and 100 parts of deionized water were mixed and stirred until homogeneous. The mixture was heated to 75°C and kept at that temperature for 4 hours. After cooling to room temperature, 15 parts of bisphenol A polysulfone (PSF), 75 parts of dichloromethane, and 20 parts of tetrahydrofuran were added. The mixture was stirred at 12,000 rpm for 3 minutes to form an emulsion. The emulsion was then added dropwise to 300 parts of a 2 wt% polyvinyl alcohol solution and stirred at 5,000 rpm for 10 minutes. The mixture was then heated to 40°C and stirred continuously for 5 hours. After centrifugation and washing, the mixture was dried at 50°C for 2 hours to obtain PNIPAM@PSF core-shell capsules.

[0053] 120 parts of 60wt% PTFE emulsion, 25 parts of polyethylene oxide, 255 parts of anhydrous ethanol, 18 parts of PNIPAM@PSF core-shell capsules, and 100 parts of deionized water were mixed and stirred at 400 rpm for 2.5 h. The mixture was then degassed under a negative pressure of -0.07 MPa for 20 min to obtain an electrospinning solution. The solution was fed into an electrospinning machine with the electrospinning voltage set to 40 kV, the collection distance to 20 cm, and the liquid supply rate to 1.0 mL / h. The electrospinning solution was deposited onto a collecting roller and placed in a sintering furnace. The temperature was increased to 345 °C at a rate of 4 °C / min and sintered for 12 min. After cooling to room temperature, a nanofiber membrane was obtained.

[0054] 130 parts of PET fiber cloth and 1000 parts of 3wt% sodium hydroxide solution were treated at 98℃ for 30 min, filtered and washed to obtain alkalized PET fiber cloth. 60 parts of N,N-dimethylformamide and 60 parts of ethylene glycol were mixed, heated to 90℃, and the alkalized PET fiber cloth was added and soaked for 10 min for swelling treatment. 350 parts of hexafluorobutyl acrylate (HFBA), 50 parts of 2-hydroxyethyl acrylate (HEA), 900 parts of anhydrous ethanol, 100 parts of ethyl acetate and 200 parts of deionized water were mixed to prepare HFBA / HEA impregnation solution. The swollen alkalized PET fiber cloth was placed in 1600 parts of HFBA / HEA impregnation solution, heated to 80℃ for 3 h, cooled to 10℃ for 30 min, dehydrated by rollers to a moisture content of 25%, dried at 110℃ for 3 min, and baked at 170℃ for 80 s to obtain the outer base fabric.

[0055] 35 parts (35 wt%) of polyurethane resin, 60 parts of DMF, 6 parts of propylene glycol methyl ether, 0.3 parts of RH-9510 defoamer, and 10 parts of deionized water were mixed and stirred at 500 rpm for 2 hours. The mixture was then filtered through a 0.45 μm filter to obtain the PU coating liquid.

[0056] After the outer base fabric and nanofiber membrane are laminated, they are fed into a hot press laminating machine and hot-pressed at a temperature of 150℃ and a pressure of 0.35MPa at a speed of 5m / min. After cooling to 50℃, a PET / PTFE composite material is obtained. A PU coating liquid is uniformly coated onto one side of the nanofiber membrane of the PET / PTFE composite material and heated to 130℃ for 6 minutes to obtain the inner membrane. After cooling to room temperature, it is allowed to stand for 30 hours to age, resulting in a breathable and waterproof composite fabric composed of outer base fabric 1, nanofiber membrane 2 and inner membrane 3.

[0057] Example 4

[0058] Five parts of N-isopropylacrylamide (PNIPAM), 0.2 parts of N,N'-methylenebisacrylamide, 0.1 parts of ammonium persulfate, and 80 parts of deionized water were mixed and stirred until homogeneous. The mixture was heated to 65°C and kept at that temperature for 2 hours. After cooling to room temperature, 10 parts of bisphenol A polysulfone (PSF), 60 parts of dichloromethane, and 10 parts of tetrahydrofuran were added. The mixture was stirred at 8000 rpm for 1 minute to form an emulsion. The emulsion was then added dropwise to 200 parts of a 1 wt% polyvinyl alcohol solution and stirred at 3000 rpm for 5 minutes. The mixture was heated to 30°C and stirred continuously for 4 hours. After centrifugation and washing, the mixture was dried at 40°C for 1 hour to obtain PNIPAM@PSF core-shell capsules.

[0059] 90 parts of 60wt% PTFE emulsion, 15 parts of polyethylene oxide, 220 parts of anhydrous ethanol, 15 parts of PNIPAM@PSF core-shell capsules, and 80 parts of deionized water were mixed and stirred at 300 rpm for 1.5 h. The mixture was then degassed under a negative pressure of -0.09 MPa for 10 min to obtain an electrospinning solution. This solution was fed into an electrospinning machine with the electrospinning voltage set to 30 kV, the collection distance to 15 cm, and the liquid supply rate to 0.6 mL / h. The electrospinning solution was deposited onto a collecting roller and placed in a sintering furnace. The furnace was heated to 340 °C at a rate of 2 °C / min and sintered for 8 min. After cooling to room temperature, a nanofiber membrane was obtained.

[0060] 120 parts of PET fiber cloth and 850 parts of 3wt% sodium hydroxide solution were treated at 95℃ for 20 min, filtered and washed to obtain alkalized PET fiber cloth. 250 parts of hexafluorobutyl acrylate (HFBA), 30 parts of 2-hydroxyethyl acrylate (HEA), 700 parts of anhydrous ethanol, 50 parts of ethyl acetate and 100 parts of deionized water were mixed to prepare HFBA / HEA impregnation solution. The alkalized PET fiber cloth was placed in 1100 parts of HFBA / HEA impregnation solution, heated to 70℃ and kept at that temperature for 2 h, dehydrated by rollers to a moisture content of 15%, dried at 100℃ for 1 min, and baked at 150℃ for 40 s to obtain the outer base fabric.

[0061] 30 parts of 35wt% polyurethane resin, 50 parts of DMF, 4 parts of propylene glycol methyl ether, 0.1 parts of RH-9510 defoamer and 8 parts of deionized water were mixed and stirred at 300 rpm for 1 hour. The mixture was then filtered through a 0.45 μm filter to obtain the PU coating liquid.

[0062] After the outer base fabric and nanofiber membrane are laminated, they are fed into a hot press laminating machine and hot-pressed at a temperature of 130℃ and a pressure of 0.25MPa at a speed of 3m / min. After cooling to 30℃, a PET / PTFE composite material is obtained. A PU coating liquid is uniformly coated onto one side of the nanofiber membrane of the PET / PTFE composite material and heated to 100℃ and kept at that temperature for 3 minutes to obtain the inner membrane. After cooling to room temperature, the membrane is allowed to stand and age for 20 hours to obtain a breathable and waterproof composite fabric composed of an outer base fabric 1, a nanofiber membrane 2, and an inner membrane 3.

[0063] Example 5

[0064] Eight parts of N-isopropylacrylamide (PNIPAM), 0.25 parts of N,N'-methylenebisacrylamide, 0.2 parts of ammonium persulfate, and 90 parts of deionized water were mixed and stirred until homogeneous. The mixture was heated to 70°C and kept at that temperature for 3 hours. After cooling to room temperature, 12 parts of bisphenol A polysulfone (PSF), 70 parts of dichloromethane, and 15 parts of tetrahydrofuran were added. The mixture was stirred at 10,000 rpm for 2 minutes to form an emulsion. The emulsion was then added dropwise to 250 parts of a 1.5 wt% polyvinyl alcohol solution and stirred at 4,000 rpm for 7 minutes. The mixture was heated to 35°C and stirred continuously for 4.5 hours. After centrifugation and washing, the mixture was dried at 45°C for 1.5 hours to obtain PNIPAM@PSF core-shell capsules.

[0065] 110 parts of 60wt% PTFE emulsion, 20 parts of polyethylene oxide, 240 parts of anhydrous ethanol, 17 parts of PNIPAM@PSF core-shell capsules, and 90 parts of deionized water were mixed and stirred at 350 rpm for 2 h. The mixture was then degassed for 15 min under a negative pressure of -0.08 MPa to obtain an electrospinning solution. The solution was fed into an electrospinning machine with the electrospinning voltage set to 35 kV, the collection distance to 17 cm, and the liquid supply rate to 0.85 mL / h. The electrospinning solution was deposited onto a collecting roller and placed in a sintering furnace. The temperature was increased to 342 °C at a rate of 3 °C / min and sintered for 10 min. After cooling to room temperature, a nanofiber membrane was obtained.

[0066] 125 parts of PET fiber cloth and 950 parts of 3wt% sodium hydroxide solution were treated at 96℃ for 25 min, filtered and washed to obtain alkalized PET fiber cloth. 300 parts of hexafluorobutyl acrylate (HFBA), 4 parts of 2-hydroxyethyl acrylate (HEA), 800 parts of anhydrous ethanol, 75 parts of ethyl acetate and 150 parts of deionized water were mixed to prepare HFBA / HEA impregnation solution. The alkalized PET fiber cloth was placed in 1300 parts of HFBA / HEA impregnation solution, heated to 75℃ and held at that temperature for 2.5 h, dehydrated by rollers to a moisture content of 20%, dried at 105℃ for 2 min, and baked at 160℃ for 60 s to obtain the outer base fabric.

[0067] 32 parts (35 wt%) of polyurethane resin, 55 parts of DMF, 5 parts of propylene glycol methyl ether, 0.2 parts of RH-9510 defoamer, and 9 parts of deionized water were mixed and stirred at 40 rpm for 1.5 h. The mixture was then filtered through a 0.45 μm filter to obtain the PU coating liquid.

[0068] After the outer base fabric and nanofiber membrane are laminated, they are fed into a hot press laminating machine. At a temperature of 140℃ and a pressure of 0.3MPa, they are hot-pressed at a speed of 4m / min. After cooling to 50℃, a PET / PTFE composite material is obtained. A PU coating liquid is uniformly coated onto one side of the nanofiber membrane of the PET / PTFE composite material and heated to 120℃ for 5 minutes to obtain the inner membrane. After cooling to room temperature, it is allowed to stand for aging for 25 hours to obtain a breathable and waterproof composite fabric composed of outer base fabric 1, nanofiber membrane 2 and inner membrane 3.

[0069] Example 6

[0070] Eight parts of N-isopropylacrylamide (PNIPAM), 0.5 parts of N,N'-methylenebisacrylamide, 0.3 parts of ammonium persulfate, and 100 parts of deionized water were mixed and stirred until homogeneous. The mixture was heated to 75°C and kept at that temperature for 4 hours. After cooling to room temperature, 15 parts of bisphenol A polysulfone (PSF), 75 parts of dichloromethane, and 20 parts of tetrahydrofuran were added. The mixture was stirred at 12,000 rpm for 3 minutes to form an emulsion. The emulsion was then added dropwise to 300 parts of a 2 wt% polyvinyl alcohol solution and stirred at 5,000 rpm for 10 minutes. The mixture was then heated to 40°C and stirred continuously for 5 hours. After centrifugation and washing, the mixture was dried at 50°C for 2 hours to obtain PNIPAM@PSF core-shell capsules.

[0071] 120 parts of 60wt% PTFE emulsion, 25 parts of polyethylene oxide, 255 parts of anhydrous ethanol, 18 parts of PNIPAM@PSF core-shell capsules, and 100 parts of deionized water were mixed and stirred at 400 rpm for 2.5 h. The mixture was then degassed under a negative pressure of -0.07 MPa for 20 min to obtain an electrospinning solution. The solution was fed into an electrospinning machine with the electrospinning voltage set to 40 kV, the collection distance to 20 cm, and the liquid supply rate to 1.0 mL / h. The electrospinning solution was deposited onto a collecting roller and placed in a sintering furnace. The temperature was increased to 345 °C at a rate of 4 °C / min and sintered for 12 min. After cooling to room temperature, a nanofiber membrane was obtained.

[0072] 130 parts of PET fiber cloth and 1000 parts of 3wt% sodium hydroxide solution were treated at 98℃ for 30 min, filtered and washed to obtain alkalized PET fiber cloth. 350 parts of hexafluorobutyl acrylate (HFBA), 50 parts of 2-hydroxyethyl acrylate (HEA), 900 parts of anhydrous ethanol, 100 parts of ethyl acetate and 200 parts of deionized water were mixed to prepare HFBA / HEA impregnation solution. The swollen alkalized PET fiber cloth was placed in 1600 parts of HFBA / HEA impregnation solution, heated to 80℃ and kept at that temperature for 3 h, dehydrated by rollers to a moisture content of 25%, dried at 110℃ for 3 min, and baked at 170℃ for 80 s to obtain the outer base fabric.

[0073] 35 parts (35 wt%) of polyurethane resin, 60 parts of DMF, 6 parts of propylene glycol methyl ether, 0.3 parts of RH-9510 defoamer, and 10 parts of deionized water were mixed and stirred at 500 rpm for 2 hours. The mixture was then filtered through a 0.45 μm filter to obtain the PU coating liquid.

[0074] After the outer base fabric and nanofiber membrane are laminated, they are fed into a hot press laminating machine and hot-pressed at a temperature of 150℃ and a pressure of 0.35MPa at a speed of 5m / min. After cooling to 50℃, a PET / PTFE composite material is obtained. A PU coating liquid is uniformly coated onto one side of the nanofiber membrane of the PET / PTFE composite material and heated to 130℃ for 6 minutes to obtain the inner membrane. After cooling to room temperature, it is allowed to stand for 30 hours to age, resulting in a breathable and waterproof composite fabric composed of outer base fabric 1, nanofiber membrane 2 and inner membrane 3.

[0075] The present invention also includes comparative examples and related experiments.

[0076] Comparative Example 1

[0077] The only difference from Example 1 is that PNIPAM@PSF core-shell capsules were not added; all other components and preparation steps were exactly the same, resulting in a breathable and waterproof composite fabric.

[0078] Comparative Example 2

[0079] The only difference from Example 1 is that the alkalized PET fiber cloth was not soaked in HFBA / HEA impregnation solution, while the other components and preparation steps were completely the same, resulting in a breathable and waterproof composite fabric.

[0080] Comparative Example 3

[0081] The only difference from Example 1 is that bisphenol A polysulfone was not added; all other components and preparation steps were exactly the same, resulting in a breathable and waterproof composite fabric.

[0082] Performance testing:

[0083] The air permeability of the breathable and waterproof composite fabrics prepared in Examples 1-6 and Comparative Examples 1-3 was tested according to the national standard GB / T5453-2025 "Determination of air permeability of textile fabrics". The test results are shown in Table 1.

[0084] The waterproof performance of the breathable and waterproof composite fabrics prepared in Examples 1-6 and Comparative Examples 1-3 was tested by hydrostatic pressure test according to the national standard GB / T4744-2013 "Test and Evaluation of Waterproof Performance of Textiles - Hydrostatic Pressure Method". The test results are shown in Table 1.

[0085] The mechanical strength of the breathable and waterproof composite fabrics prepared in Examples 1-6 and Comparative Examples 1-3 was tested according to the national standard GB / T3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break - Strip Method" for breaking strength and elongation at break; the tearing strength was tested according to the national standard GB / T 3917.1-2009 "Textiles - Tear Properties of Fabrics - Part 1: Determination of Tear Strength by Impact Pendulum Method". The test results are shown in Table 1.

[0086] Table 1

[0087]

[0088] like Figure 1 As shown, the breathable and waterproof composite fabrics prepared in Examples 1 to 6 include an outer base fabric 1, a nanofiber membrane 2, and an inner membrane 3 stacked sequentially.

[0089] As shown in Table 1, compared with Examples 4-6, the hydrostatic pressure, tensile strength, elongation at break and tear strength of the breathable and waterproof composite fabric in Examples 1-3 are all improved. This indicates that the outer base fabric can improve the waterproof performance and mechanical strength of the breathable and waterproof composite fabric after swelling-recrystallization treatment.

[0090] Based on the test results in Table 1, compared to Example 1, the breathability of the breathable and waterproof composite fabric in Comparative Example 1, which did not contain PNIPAM@PSF core-shell capsules, was significantly reduced. This indicates that PNIPAM@PSF core-shell capsules help improve the breathability of the breathable and waterproof composite fabric. Compared to Example 1, the hydrostatic pressure, tensile strength, elongation at break, and tear strength of the breathable and waterproof composite fabric in Comparative Example 2 were all reduced. This indicates that immersion treatment of alkalized PET fiber cloth in HFBA / HEA impregnation solution helps improve the waterproof performance and mechanical strength of the breathable and waterproof composite fabric. Compared to Example 1, the hydrostatic pressure of the breathable and waterproof composite fabric in Comparative Example 3, which did not contain bisphenol A polysulfone, was significantly reduced. This indicates that bisphenol A polysulfone helps improve the waterproof performance of the breathable and waterproof composite fabric.

[0091] The above are preferred embodiments of the present invention. Those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a breathable and waterproof composite fabric, wherein the fabric comprises at least an outer base fabric, a nanofiber membrane, and an inner membrane stacked sequentially, characterized in that, The preparation steps include the following: S1. PTFE emulsion, polyethylene oxide, anhydrous ethanol, PNIPAM@PSF core-shell capsules and deionized water are mixed and stirred, degassed under negative pressure, electrospun and sintered to obtain nanofiber membranes. S2. The alkalized PET fiber cloth is placed in HFBA / HEA impregnation solution, heated, dehydrated and dried, and baked to obtain the outer base cloth; S3. Mix and stir polyurethane resin, DMF, propylene glycol methyl ether, defoamer and deionized water to prepare PU coating liquid; S4. After laminating the outer base fabric and the nanofiber membrane, hot-press the mixture, coat the nanofiber membrane with PU coating liquid, heat it to form an inner membrane on the nanofiber membrane, cool and let it stand to obtain a breathable and waterproof composite fabric. The PNIPAM@PSF core-shell capsules are prepared by mixing and stirring N-isopropylacrylamide, N,N'-methylenebisacrylamide, ammonium persulfate and deionized water, heating and reacting, cooling, adding bisphenol A polysulfone, dichloromethane and tetrahydrofuran, stirring to form an emulsion, adding dropwise to a polyvinyl alcohol solution, heating, centrifuging and washing.

2. The method for preparing a breathable and waterproof composite fabric according to claim 1, characterized in that, In step S2, before dehydration and drying, the alkalized PET fiber cloth also undergoes heating swelling and cooling recrystallization treatment.

3. The method for preparing a breathable and waterproof composite fabric according to claim 2, characterized in that, In step S2, N,N-dimethylformamide and ethylene glycol are mixed and heated to 80-90°C. Alkaliized PET fiber cloth is added and soaked for 5-10 minutes to swell. The swollen alkaliized PET fiber cloth is placed in HFBA / HEA impregnation solution, heated to 70-80°C and kept at a constant temperature for 2-3 hours, cooled to 5-10°C and cooled for 20-30 minutes, dehydrated by rollers to a moisture content of 15%-25%, dried at 100-110°C for 1-3 minutes, and baked at 150-170°C for 40-80 seconds to obtain the outer base fabric.

4. The method for preparing a breathable and waterproof composite fabric according to claim 1, characterized in that, In step S1, PTFE emulsion, polyethylene oxide, anhydrous ethanol, PNIPAM@PSF core-shell capsules and deionized water are mixed and stirred at 300-400 rpm for 1.5-2.5 h. The mixture is then degassed for 10-20 min under a negative pressure of -0.09--0.07 MPa to obtain an electrospinning solution. This solution is then fed into an electrospinning machine for electrospinning. The temperature is increased to 340-345℃ at a rate of 2-4℃ / min and sintered for 8-12 min. The solution is then cooled to obtain a nanofiber membrane.

5. The method for preparing a breathable and waterproof composite fabric according to claim 1, characterized in that, In the preparation of the PNIPAM@PSF core-shell capsules, N-isopropylacrylamide, N,N'-methylenebisacrylamide, ammonium persulfate and deionized water are mixed and stirred, heated to 65-75℃ and kept at a constant temperature for 2-4 hours, cooled to room temperature, bisphenol A polysulfone, dichloromethane and tetrahydrofuran are added, and stirred at 8000-12000 rpm for 1-3 minutes to form an emulsion. The emulsion is added dropwise to a 1-2 wt% polyvinyl alcohol solution, stirred at 3000-5000 rpm for 5-10 minutes, heated to 30-40℃ and stirred for 4-5 hours, centrifuged and washed, and dried at 40-50℃ for 1-2 hours to obtain the product.

6. The method for preparing a breathable and waterproof composite fabric according to claim 1, characterized in that, In step S3, polyurethane resin, DMF, propylene glycol methyl ether, RH-9510 defoamer and deionized water are mixed and stirred at 300~500 rpm for 1~2 hours, and then filtered through a 0.45μm filter to obtain PU coating liquid.

7. The method for preparing a breathable and waterproof composite fabric according to claim 6, characterized in that, In step S4, after the outer base fabric and the nanofiber membrane are laminated, they are hot-pressed at a temperature of 130~150℃ and a pressure of 0.25~0.35MPa at a speed of 3~5m / min. After cooling to 30~50℃, the PU coating liquid is uniformly coated onto the nanofiber membrane. The membrane is then heated to 100~130℃ and kept at a constant temperature for 3~6 minutes to form an inner membrane on the nanofiber membrane. After cooling to room temperature, the membrane is allowed to stand and age for 20~30 hours to obtain a breathable and waterproof composite fabric.

8. The method for preparing a breathable and waterproof composite fabric according to claim 1, characterized in that, The alkalized PET fiber cloth is prepared by mixing PET fiber cloth and sodium hydroxide solution, maintaining the temperature at 95~98℃ for 20~30 minutes, and then filtering and washing.

9. A breathable and waterproof composite fabric, characterized in that, The breathable and waterproof composite fabric is prepared using the method described in any one of claims 1 to 8. The nanofiber membrane comprises the following raw materials in parts by weight: 90-120 parts of 60wt% PTFE emulsion, 15-25 parts of polyethylene oxide, 220-255 parts of anhydrous ethanol, 15-18 parts of PNIPAM@PSF core-shell capsules, and 80-100 parts of deionized water; the outer base fabric comprises the following raw materials in parts by weight: 1 part of alkalized PET fiber cloth. The inner membrane is made of PU coating liquid, which comprises the following raw materials in parts by weight: 20-130 parts of polyurethane resin, 40-60 parts of DMF, 4-6 parts of propylene glycol methyl ether, 0.1-0.3 parts of RH-9510 defoamer, and 8-10 parts of deionized water.

10. The breathable and waterproof composite fabric according to claim 9, characterized in that, The PNIPAM@PSF core-shell capsule comprises the following raw materials in parts by weight: 5-8 parts of N-isopropylacrylamide, 0.2-0.5 parts of N,N'-methylenebisacrylamide, 0.1-0.3 parts of ammonium persulfate, 80-100 parts of deionized water, 10-15 parts of bisphenol A polysulfone, 60-75 parts of dichloromethane, and 10-20 parts of tetrahydrofuran; the alkalized PET fiber cloth comprises the following raw materials in parts by weight: 120-130 parts of PET fiber cloth and 850-1000 parts of 3wt% sodium hydroxide solution.

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